Self-heating biosensor chip and preparation method thereof, and virus detection method

Abstract

A self-heating biosensor chip and a preparation method thereof, and a virus detection method, belong to the field of biological detection. The self-heating biosensor chip includes a substrate, a silicon dioxide layer, a detection unit, and a heating electrode. The silicon dioxide layer is formed and covers the support surface of the substrate, and the detection unit includes: a carbon film and two metal electrodes respectively formed on the support surface of the silicon dioxide layer, the two metal electrodes are respectively electrically connected to the two ends of the carbon film, and the carbon film is configured to contact the sample solution, and the carbon film has a modified surface for modifying biological macromolecules. The heating electrode is formed in the substrate, and the heating surface of the heating electrode abuts the silicon dioxide layer to heat the carbon film by heat conduction. The working voltage of the heating electrode is configured to be 20 to 35 mV, and the thickness of the silicon dioxide layer between the carbon film and the heating electrode is 150 to 400 nm. It can solve the problem that the biosensor cannot be reused, so as to improve the utilization rate and reduce the detection cost.

Description

Technical Field

[0001] The present application relates to the field of biological detection, and in particular, to a self-heating biosensor chip and a preparation method thereof, and a virus detection method. Background Art

[0002] Bioelectric sensors are different from traditional biological detection technologies. They convert virus detection into electrical signal detection, which is faster and more efficient. However, in most cases, biosensors, such as graphene biosensors, can only be used once, with low reuse rates, resulting in high production and detection costs. Summary of the invention

[0003] The present application provides a self-heating biosensor chip and a preparation method thereof, and a virus detection method, which can solve the problem that the biosensor cannot be reused.

[0004] The embodiment of the present application is implemented as follows:

[0005] In a first aspect, the present application example provides a self-heating biosensor chip, which includes a substrate, a silicon dioxide layer, at least one detection unit, and a heating electrode.

[0006] The substrate has a supporting surface.

[0007] A silicon dioxide layer is formed and covers the support surface, and the silicon dioxide layer has a bearing surface away from the substrate.

[0008] Each detection unit includes: a carbon film formed on a supporting surface and two metal electrodes, the two metal electrodes are electrically connected to the two ends of the carbon film, the carbon film is configured to contact the sample solution, the carbon film has a modified surface, and the modified surface is used to modify the biological macromolecules that can detect the target in the sample solution. The heating electrode is formed in the substrate, and the heating surface of the heating electrode abuts against the silicon dioxide layer to heat the carbon film by heat conduction.

[0009] The operating voltage of the heating electrode is configured to be 20 to 35 mV, and the thickness of the silicon dioxide layer between the carbon film and the heating electrode is 150 to 400 nm.

[0010] In the above implementation process, after the self-heating biosensor chip detection is completed, based on the cooperation of the heating electrode with a working voltage of 20 to 35 mV and the silicon dioxide layer with a thickness of 150 to 400 nm located between the carbon film and the heating electrode, the temperature of the carbon film is ensured to be appropriate, which can not only remove the viruses and residual biological solutions bound to the biological macromolecules on the surface of the carbon film, but also effectively avoid the inactivation of the biological macromolecules after the removal of the viruses, thereby realizing the reuse of the self-heating biosensor chip and effectively reducing the detection cost; and because the carbon film is an ultra-high thermal conductivity material, if the carbon film is directly heated, the voltage required is very large, which not only increases the power consumption but also easily damages the sensor itself. The present application utilizes the setting of a silicon dioxide layer with a thickness of 150 to 400 nm between the carbon film and the heating electrode to ensure that the working voltage for heating the carbon film to a preset temperature is only 20 to 35 mV, effectively reducing energy consumption.

[0011] In combination with the first aspect, in a possible implementation, the carbon material in the carbon film includes at least one of graphene, fullerene and carbon nanotube.

[0012] Optionally, the carbon material in the carbon film is graphene.

[0013] Chips made of graphene have good sensitivity to viruses.

[0014] In combination with the first aspect, in a possible embodiment, the modified surface is modified with a biological macromolecule, and the biological macromolecule is a viral antigen, a viral antibody or a nucleic acid probe.

[0015] In combination with the first aspect, in a possible implementation manner, the number of the detection units is at least two, and any two adjacent detection units are arranged at intervals.

[0016] In the above implementation process, the number of detection units is at least two. Therefore, according to actual needs, the same biomacromolecule can be modified on the carbon membrane in each detection unit to conduct parallel experiments or control experiments, or different biomacromolecules can be modified on the carbon membrane in each detection unit to simultaneously detect different sample solutions and improve detection efficiency.

[0017] In combination with the first aspect, in a possible implementation scheme, the number of heating electrodes corresponds to the number of detection units, each heating electrode is arranged at the positive projection of the detection unit on the carrying surface, and any two adjacent heating electrodes are arranged at intervals.

[0018] In the above implementation process, it is possible to individually control whether the heating electrode corresponding to each detection unit is working. Combined with the specific setting position of each heating electrode, it is possible to effectively avoid the heating electrode corresponding to one detection unit from affecting another adjacent detection unit when it is working.

[0019] In combination with the first aspect, in a possible implementation, the self-heating biosensor chip further includes a gate electrode, which is disposed on the carrying surface and is configured to adjust the field effect of each carbon film.

[0020] The gate electrode is used to adjust the field effect of each carbon film, thereby adjusting the current passing through the carbon film.

[0021] In combination with the first aspect, in a possible implementation manner, the substrate is a silicon wafer, and the material of the silicon dioxide layer is silicon dioxide.

[0022] In a second aspect, the present application example provides a method for preparing a self-heating biosensor chip, which comprises:

[0023] A heating electrode is deposited on the supporting surface of the substrate, and then a silicon dioxide layer is deposited on the remaining supporting surface and the surface of the heating electrode, and the silicon dioxide layer is etched to expose the pad of the heating electrode.

[0024] The side of the silicon dioxide layer away from the substrate is used as a carrying surface, a patterned carbon film is formed on the carrying surface, two metal electrodes electrically connected to the two ends of the carbon film are deposited on the carrying surface, the carrying surface is encapsulated and the carbon film, the pads of each metal electrode and the pads of the heating electrode are exposed.

[0025] The exposed carbon film is modified with biomacromolecules, wherein the biomacromolecules are viral antigens, viral antibodies or nucleic acid probes.

[0026] The operating voltage of the heating electrode is configured to be 20 to 35 mV, and the thickness of the substrate between the carbon film and the heating electrode is 150 to 400 nm.

[0027] The preparation method is simple to operate, and the prepared self-heating biosensor chip can be reused, effectively improving detection efficiency and reducing costs.

[0028] In combination with the second aspect, in a possible implementation, after depositing two metal electrodes on the carrier surface, the preparation method further includes depositing a gate electrode on the carrier surface and exposing the gate electrode after packaging, and the gate electrode is configured to adjust the field effect of the carbon film.

[0029] In conjunction with the second aspect, in a possible embodiment, the biomacromolecule is an antibody, and the step of modifying the biomacromolecule with a carbon film comprises:

[0030] The surface of the carbon film was functionalized with a PBASE / ethanol solution to form a PBASE / carbon film.

[0031] Spot the antibody / PBS solution on the PBASE / carbon membrane, dry it, then use blocking solution to block the PBASE that is not bound to the antibody, and then wash it.

[0032] By using the above modification method, the antibody is stably bound to the carbon membrane via PBASE, and the PBASE that is not bound to the antibody is blocked to ensure that the biomacromolecule can specifically bind to the antigen. At the same time, PBASE, as a connecting molecule, can ensure that the antibody can stably bind to the carbon membrane within the heating temperature range and will not detach from the carbon membrane.

[0033] In a second aspect, the present application example provides a virus detection method, the virus detection method comprising:

[0034] The self-heating biosensor chip provided in the first aspect of the present application or the self-heating biosensor chip prepared by the preparation method provided in the second aspect is obtained.

[0035] The sample solution is brought into contact with the carbon film, and two metal electrodes are used to detect the current at both ends of the carbon film. If the current at both ends of the carbon film changes, it is determined that the sample solution contains viruses that specifically react with biological macromolecules.

[0036] The carbon film is heated by a heating electrode to desorb the virus bound to the biomacromolecules.

[0037] The above detection method is simple, and after the detection result comes out, the virus bound to the biological macromolecule can be detached by heating through the heating electrode, and the biological macromolecule still remains active, so that it can be reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 It is a schematic diagram of the structure of the self-heating biosensor chip;

[0040] Figure 2 It is a schematic diagram of the structure of the chip body;

[0041] Figure 3 for Figure 2 Schematic diagram of the structure in the middle AA direction;

[0042] Figure 4 It is a schematic diagram of the structure in which the detection unit is arranged on the surface of the silicon dioxide layer;

[0043] Figure 5 A schematic diagram of the change of current through graphene over time provided for Experimental Example 1;

[0044] Figure 6A schematic diagram showing the change of current through graphene over time under dry-firing conditions provided in Experimental Example 1;

[0045] Figure 7 Schematic diagram of the detection sensitivity of the self-heating biosensor chip;

[0046] Figure 8 A schematic diagram of the change of current through graphene over time provided for Experimental Example 3.

[0047] Icon: 10 - self-heating biosensor chip; 100 - chip body; 110 - substrate; 120 - silicon dioxide layer; 131 - carbon film; 133 - metal electrode; 140 - heating electrode; 150 - gate electrode; 170 - packaging layer; 200 - PDMS layer; 210 - sample addition slot. DETAILED DESCRIPTION

[0048] The embodiments of the present application will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0049] Example 1

[0050] See also Figure 1 as well as Figure 2 , a self-heating biosensor chip 10 includes a chip body 100 and a PDMS layer 200.

[0051] See also Figure 2 , Figure 3 as well as Figure 4 The chip body 100 includes a substrate 110 , a silicon dioxide layer 120 , a detection unit, a heating electrode 140 , a gate electrode 150 and a packaging layer 170 .

[0052] The substrate 110 has a support surface, the silicon dioxide layer 120 is formed and covered on the support surface, and the silicon dioxide layer 120 has a support surface away from the substrate 110; the gate electrode 150 and the detection unit are respectively arranged on the support surface, and the gate electrode 150 is configured to adjust the field effect of each carbon film 131. The detection unit includes a carbon film 131 formed on the support surface and two metal electrodes 133, the two metal electrodes 133 are respectively electrically connected to the two ends of the carbon film 131, the carbon film 131 is configured to contact and detect the object of action in the sample solution, the carbon film 131 has a modified surface, and the modified surface is used to modify the biomacromolecules that can detect the object of action in the sample solution, and the heating electrode 140 is formed in the substrate 110, and the heating surface of the heating electrode 140 abuts against the silicon dioxide layer 120 to heat the carbon film 131 through heat conduction.

[0053] The above arrangement can be used to make the sample solution contact with the carbon film 131, and use the two metal electrodes 133 to detect whether the current at both ends of the carbon film 131 changes, thereby determining whether the sample solution contains viruses, which are targets for specific reactions with biological macromolecules. After the determination is completed, the heating electrode 140 can be used to heat the carbon film 131 in situ by thermal conduction, so as to remove viruses and biological solutions bound to biological macromolecules on the surface of the carbon film 131 with low power consumption.

[0054] The silicon dioxide layer 120 is insulating and thermally conductive. In order to prevent the biomacromolecules on the carbon film 131 from failing due to excessive temperature during actual use, the present invention effectively solves the above problem by controlling the thickness of the silicon dioxide layer 120 between the carbon film 131 and the heating electrode 140 and the working voltage of the heating electrode 140.

[0055] The working voltage of the heating electrode 140 is configured to be 20-35 mV, and the thickness of the silicon dioxide layer 120 between the carbon film 131 and the heating electrode 140 is 150-400 nm, for example, the thickness of the silicon dioxide layer 120 between the carbon film 131 and the heating electrode 140 is 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, 250 nm, 280 nm, 300 nm, 350 nm or 400 nm, etc. Based on the specific voltage, the positional relationship between the heating electrode 140 and the carbon film 131, and the coordination of the silicon dioxide layer 120 and its thickness, it can be ensured that after the virus bound to the biomacromolecules on the surface of the carbon film 131 and the residual biological solution are removed, the inactivation of the biomacromolecules after the virus removal is effectively avoided, thereby realizing the reuse of the self-heating biosensor chip and effectively reducing energy consumption.

[0056] In this embodiment, the operating voltage of the heating electrode 140 is configured to be 35 mV, and the thickness of the silicon dioxide layer 120 between the carbon film 131 and the heating electrode 140 is 200 nm.

[0057] Among them, biological macromolecules can be prepared or purchased according to the viruses that need to be detected. At the same time, viruses include but are not limited to new coronaviruses, influenza viruses, etc. Technical personnel in this field can limit them according to actual needs, and no limitation is made here.

[0058] For example, in this embodiment, the biological macromolecule is the new coronavirus antibody Mab Mouse anti-Covid-19 N.

[0059] The substrate 110 is used to support the silicon dioxide layer 120 etc. formed on the support surface. In this embodiment, the substrate 110 is a silicon wafer, and its thickness and size can be selected according to actual needs.

[0060] In order to facilitate the control of the thickness of the silicon dioxide layer 120 between the carbon film 131 and the heating electrode 140, as shown in FIG. Figure 3 As shown, the support surface is provided with a groove, the heating electrode 140 is deposited in the groove, and the heating surface faces the opening of the groove and is flush with the support surface, that is, the depth of the groove is the same as the thickness of the heating electrode 140. For example, in this embodiment, the depth of the groove is 50nm, and the thickness of the heating electrode 140 is 50nm. The silicon dioxide layer 120 is formed and covers the support surface (the support surface without the groove) and the heating surface, so that the heating surface can transfer heat to the silicon dioxide layer 120 by heat conduction.

[0061] The number of the heating electrodes 140 is at least one, such as one, two or three, and the number of the detection units is at least one, such as one, two or three.

[0062] In the first setting provided by the present application, the number of detection units corresponds to the number of heating electrodes 140, and each heating electrode 140 is arranged at the positive projection of the detection unit on the support surface. That is, the corresponding carbon film 131 is heated separately by the heating electrode 140 corresponding to each detection unit, which is more flexible to use, and in actual use, when only the heating electrodes 140 corresponding to some of the detection units are used to remove the viruses bound to the corresponding carbon film 131 and / or dry the carbon film 131, it can avoid affecting the biomacromolecules on the idle carbon film 131 adjacent to it.

[0063] It should be noted that, in order to ensure a good heating effect, the area of ​​the heating electrode 140 is equal to or slightly larger than the area of ​​the orthographic projection.

[0064] In some optional examples of the first setting case, the number of the detection unit and the number of the heating electrode 140 are both one.

[0065] In other optional examples of the first setting, the number of detection units and the number of heating electrodes 140 are at least two, for example, the number of detection units is two, three, five, etc. At the same time, the same biomacromolecule can be modified on the carbon film 131 in different detection units according to actual needs to conduct parallel experiments or control experiments, or different biomacromolecules can be modified on the carbon film 131 in different detection units to simultaneously detect different sample solutions to improve detection efficiency.

[0066] In order to prevent the heating electrode 140 corresponding to one detection unit from affecting another adjacent detection unit when it is working, optionally, any two adjacent detection units are arranged at intervals, and any two adjacent heating electrodes 140 are arranged at intervals. It should be noted that the interval between any two adjacent detection units and the interval between any two adjacent heating electrodes 140 can be set according to the actual chip layout.

[0067] For example, in this embodiment, the number of the detection units and the number of the heating electrodes 140 are both three, and the three heating electrodes 140 and the three detection units are arranged in an array.

[0068] In the second configuration, the number of detection units is greater than the number of heating electrodes 140 .

[0069] That is, at this time, the number of detection units is at least two, and the number of heating electrodes 140 is at least one. At this time, two adjacent carbon films 131 are arranged at intervals, and the heating electrode 140 covers the positive projection of each detection unit on the support surface.

[0070] At this time, the same biomacromolecule can be modified on the carbon film 131 in different detection units according to actual needs to conduct parallel experiments or control experiments, or different biomacromolecules can be modified on the carbon film 131 in different detection units to simultaneously detect different sample solutions and improve detection efficiency. However, it should be noted that at this time, for the sake of use effect, it is recommended that multiple detection units be heated together after use for reuse.

[0071] Among them, the carbon material in the carbon film 131 in the detection unit includes at least one of graphene, fullerene and carbon nanotubes. For example, the carbon material is graphene, fullerene or carbon nanotubes, or a mixture of any two of them, etc. They are all ultra-high thermal conductivity materials, and have modifiability and excellent electrical conductivity, and can be used as test electrodes in this application.

[0072] In this embodiment, the carbon material is graphene, and the sensitivity of the self-heating biosensor chip 10 is better.

[0073] In order to facilitate the subsequent connection with an external power source and the detection operation, the silicon dioxide layer 120 is provided with a first opening (not shown) for exposing the pad of the heating electrode 140 .

[0074] The encapsulation layer 170 is formed on the supporting surface to encapsulate the silicon dioxide layer 120 , the carbon film 131 , the first metal electrode 133 , the second metal electrode 133 and the gate electrode 150 .

[0075] In which, the encapsulation layer 170 is provided with a third opening for respectively exposing the gate electrode 150 and its pad, the pad of the first metal electrode 133, the pad of the second metal electrode 133 and the pad of the heating electrode 140, and a second opening for exposing the carbon film 131, wherein the third opening for exposing the pad of the heating electrode 140 is connected to the first opening.

[0076] The PDMS layer 200 is disposed on the side of the encapsulation layer 170 away from the silicon dioxide layer 120. PDMS (polydimethylsiloxane) has the advantages of excellent flexibility, transparency, fluidity and biocompatibility, and its thickness can be set according to actual needs. For example, the thickness of the PDMS layer 200 in this embodiment is 2 mm.

[0077] The PDMS layer 200 is provided with three fourth openings corresponding to the second openings one by one, and the three fourth openings are arranged at intervals. The cross-sectional area of ​​each fourth opening is larger than the cross-sectional area of ​​the second opening, and the projection of the fourth opening on the bearing surface completely covers the second opening. The fourth openings are connected with the second openings to form a stepped groove serving as a sample adding groove 210. The sample adding groove 210 utilizes the fact that the cross-sectional area of ​​the fourth openings is larger than the cross-sectional area of ​​the second opening to facilitate the addition of the detection sample solution. At the same time, since the height of the carbon film 131 is lower than the encapsulation layer 170, it has sufficient depth to avoid problems such as splashing of the sample solution during actual use.

[0078] The present application provides a method for preparing the self-heating biosensor chip 10, which comprises the following steps:

[0079] S1. Provide a substrate 110.

[0080] S2 . Depositing the heating electrode 140 on the supporting surface of the substrate 110 , then depositing the silicon dioxide layer 120 on the remaining supporting surface and the surface of the heating electrode 140 , and etching the silicon dioxide layer 120 to expose the pad of the heating electrode 140 .

[0081] S3. Use the side of the silicon dioxide layer 120 away from the substrate 110 as a carrying surface, form a patterned carbon film 131 on the carrying surface, deposit two metal electrodes 133 electrically connected to the two ends of the carbon film 131 on the carrying surface, and then deposit a gate electrode 150 configured to adjust the field effect of the carbon film 131 on the carrying surface to obtain the chip body 100, and then use the encapsulation layer 170 to encapsulate the carrying surface and expose the carbon film 131, the pads of each metal electrode 133, the pads of the heating electrode 140 and the pads of the gate electrode 150, and then use the PDMS layer 200 to cover the encapsulation layer 170 and expose the carbon film 131.

[0082] After the support surface is packaged, the exposed carbon film 131 is modified with biomacromolecules, which in this embodiment are virus antibodies.

[0083] The steps of modifying biomacromolecules with carbon film 131 include:

[0084] The surface of the carbon film 131 is functionalized with a PBASE / ethanol solution to form a PBASE / carbon film 131; an antibody / PBS solution is spotted on the PBASE / carbon film 131, dried, and then a blocking solution is used to block the PBASE that is not bound to the antibody, followed by washing.

[0085] In this embodiment, 2 mM PBASE / ethanol solution was dripped on the graphene surface for 2 hours, then rinsed with ethanol and dried with an air gun to obtain PBASE / graphene. Antibody / PBS solution was dripped on PBASE / graphene for 4 hours, then rinsed with PBS solution and dried with an air gun, and then 1 M ethanolamine / PBS was dripped for 1 hour to block PBASE, and then washed to obtain blocked antibody / PBASE / graphene.

[0086] The steps of preparing the chip body 100 may be performed using a photolithography process.

[0087] In this embodiment, the chip body 100 is prepared in the following manner:

[0088] Photoresist is spin-coated on the supporting surface of the silicon wafer and subjected to UV exposure to obtain a patterned groove etching area. The patterned groove etching area is etched by an inductively coupled plasma device to obtain a groove with an etching depth of 50nm. A heating electrode 140 with a thickness of 50nm is deposited in the groove, and the photoresist is removed to leave the heating electrode 140.

[0089] A silicon dioxide layer 120 with a thickness of 200 nm is deposited on the support surface, and the prepared heating electrode 140 is covered with the silicon dioxide layer 120. Then, photoresist is spin-coated on the support surface of the silicon dioxide layer 120, and ultraviolet exposure is performed to form a pad exposure area corresponding to the pad of the heating electrode 140, and then the pad exposure area is etched to expose the pad of the heating electrode 140, and the photoresist is removed.

[0090] The graphene is transferred to a supporting surface, and then a photoresist is spin-coated on the graphene surface and subjected to ultraviolet exposure. The exposed graphene is etched using a plasma cleaner to obtain patterned graphene.

[0091] Then, photoresist is spin-coated on the surface of the graphene and the carrier surface, and ultraviolet exposure is performed to form two metal electrode deposition areas corresponding to the two ends of the graphene film. After a metal electrode 133 electrically connected to the graphene is deposited in each metal electrode deposition area, the photoresist is removed.

[0092] Photoresist is spin-coated on the carrier surface and subjected to UV exposure to form a gate electrode deposition area, a gate electrode 150 is deposited in the gate electrode deposition area, the photoresist is removed, and then an encapsulation layer 170 is used to encapsulate the carrier surface and expose the carbon film 131, the pads of each metal electrode 133, and the pads of the heating electrode 140 and the gate electrode 150.

[0093] The present application also provides a virus detection method, which is performed using the self-heating biosensor chip 10, and the virus detection method includes:

[0094] The sample solution is brought into contact with the carbon film 131 , and the current at both ends of the carbon film 131 is detected using two metal electrodes 133 . If the current at both ends of the carbon film 131 changes, it is determined that the sample solution contains viruses that specifically react with biological macromolecules.

[0095] After the test is completed, the carbon film 131 is heated by heat conduction using the heating electrode 140 to desorb the virus bound to the biomacromolecule.

[0096] Repeat Example 1 and prepare 5 self-heating biosensor chips 10 in the same manner, respectively serving as the first self-heating biosensor chip, the second self-heating biosensor chip, the third self-heating biosensor chip, the fourth self-heating biosensor chip and the fifth self-heating biosensor chip, to carry out the following test examples.

[0097] Test Example 1

[0098] The antigen SARS-CoV-2 Nucleocapsid-His recombinant Protein was added dropwise to the sample addition groove corresponding to any one of the detection units of the first self-heating biosensor chip prepared in Example 1, and the heating electrode corresponding to the sample addition groove was started to work at 750 s, and the working voltage of the heating electrode was 35 mV, and the following was obtained: Figure 5 Shown is a graph of the current passing through graphene as a function of time.

[0099] according to Figure 5It can be seen that the antibody on the graphene surface is bound to the antigen during 0-750s. The heating electrode is powered on at 750s. As time goes by, the antigen gradually detaches from the antibody. At this time, the current begins to rise, and finally detaches completely, and the current curve is stable. After the antigen is added again, the antibody and the antigen are quickly combined, causing the current to drop and return to the previous value, indicating that the antibody is not inactivated and the antigen can still bind to the antibody.

[0100] The experiment was repeated using the remaining two detection units, and a similar schematic diagram of the change of current through graphene over time was obtained, indicating that the working voltage of the heating electrode was 35mV, the antibody was not inactivated, and the antigen could still bind to the antibody.

[0101] At the same time, it was found during the experiment that the change of current passing through graphene over time can be used to determine whether dry burning occurs. Figure 6 As shown, the antigen SARS-CoV-2 Nucleocapsid-His recombinant Protein is added dropwise to the sample addition groove corresponding to any one of the detection units of the second self-heating biosensor chip prepared in Example 1, and the heating electrode corresponding to the sample addition groove is started to work at 1030s, and the working voltage of the heating electrode is 35mV.

[0102] Among them, combined Figure 5 as well as Figure 6 It can be seen that in the antibody + antigen stage, the current is relatively stable, and then after the heating electrode works ( Figure 6 In the figure, the heating electrode is started at about 1030s, and no additional antigen is added. It can be seen that the antigen is separated from the antibody, causing the current to increase to a stable state, and then the current decreases instantaneously, indicating that dry burning occurs at this time. That is, the above schematic diagram of the change of current through graphene over time can be used to determine whether dry burning occurs.

[0103] Test Example 2

[0104] The sensitivity test of the third self-heating biosensor chip prepared in Example 1 was performed. The sensitivity test operation steps included: firstly adding a 1x PBS solution without adding antigen (SARS-CoV-2 Nucleocapsid-His recombinant Protein), then adding a 10% PBS solution with a concentration of 10% PBS solution, and then adding a 10% PBS solution with a concentration of 10% PBS solution. -18 ~10 -8 The 1x PBS solution of the antigen (SARS-CoV-2 Nucleocapsid-His recombinant Protein) was added. As the concentration of the antigen in the solution was changed, the current changed. The sensitivity was obtained by using the change trend of the current. The results are as follows: Figure 7 shown.

[0105] according to Figure 7 It can be seen that the third self-heating biosensor chip can -18 The above test was repeated on the fourth self-heating biosensor chip prepared in Example 1, and similar results were obtained.

[0106] Test Example 3

[0107] After adding 1 nM of the antigen SARS-CoV-2 Nucleocapsid-His recombinant Protein to the sample addition groove corresponding to any one of the detection units of the fifth self-heating biosensor chip prepared in Example 1, power is turned on and the heating electrode corresponding to the sample addition groove is operated. The operating voltage of the heating electrode is 45 mV, and the following is obtained: Figure 8 Schematic diagram showing the change of current passing through graphene over time.

[0108] according to Figure 8 ,It can be seen that when the working voltage of the heating electrode is 45mV, the heating temperature is very high. After heating, the antibody is inactivated, and after adding the antigen, the current cannot return to its original value.

[0109] In summary, the self-heating biosensor chip and its preparation method, as well as the virus detection method, can solve the problem that the biosensor cannot be reused, and at the same time, the power consumption is low during repeated use, effectively reducing the detection cost.

[0110] The above are only specific embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A self-heating biosensor chip, characterized in that: include: a substrate having a support surface; A silicon dioxide layer formed on and covering the support surface, wherein the silicon dioxide layer has a bearing surface away from the substrate; at least one detection unit, each of the detection units comprising: a carbon film and two metal electrodes respectively formed on the support surface, the two metal electrodes being electrically connected to two ends of the carbon film respectively, the carbon film being configured to contact a sample solution, the carbon film having a modified surface, the modified surface being used to modify a biomacromolecule capable of detecting an action target in the sample solution; and a heating electrode formed in the substrate, wherein a heating surface of the heating electrode abuts against the silicon dioxide layer to heat the carbon film by heat conduction; The operating voltage of the heating electrode is configured to be 20-35 mV, and the thickness of the silicon dioxide layer between the carbon film and the heating electrode is 150-400 nm; The carbon material in the carbon film includes at least one of graphene, fullerene and carbon nanotube; The number of the heating electrodes corresponds to the detection units one by one, each of the heating electrodes is arranged at the positive projection of the detection unit on the support surface, and any two adjacent heating electrodes are arranged at intervals.

2. The self-heating biosensor chip according to claim 1, characterized in that: The carbon material in the carbon film is graphene.

3. The self-heating biosensor chip according to claim 1, characterized in that: The modified surface is modified with the biomacromolecule, and the biomacromolecule is a viral antigen, a viral antibody or a nucleic acid probe.

4. The self-heating biosensor chip according to claim 1, characterized in that: The number of the detection units is at least two, and any two adjacent detection units are arranged at an interval.

5. The self-heating biosensor chip according to any one of claims 1 to 4, characterized in that: The invention also includes a gate electrode, which is disposed on the supporting surface and is configured to adjust the field effect of each of the carbon films.

6. A method for preparing a self-heating biosensor chip as claimed in claim 1, characterized in that: include: providing a substrate; Depositing the heating electrode on the supporting surface of the substrate, then depositing a silicon dioxide layer on the remaining supporting surface and the surface of the heating electrode, and etching the silicon dioxide layer to expose the pad of the heating electrode; Using the side of the silicon dioxide layer away from the substrate as a bearing surface, forming the patterned carbon film on the bearing surface, depositing two metal electrodes electrically connected to the two ends of the carbon film on the bearing surface, encapsulating the bearing surface and exposing the carbon film, the pads of each metal electrode and the pads of the heating electrode; The exposed modified surface of the carbon film is modified with biomacromolecules, wherein the biomacromolecules are viral antigens, viral antibodies or nucleic acid probes.

7. The preparation method according to claim 6, characterized in that: After depositing the two metal electrodes on the carrier surface, the preparation method further includes depositing a gate electrode on the carrier surface and exposing the gate electrode after the packaging, wherein the gate electrode is configured to adjust the field effect of the carbon film.

8. The preparation method according to claim 6, characterized in that: The biomacromolecule is an antibody, and the step of modifying the biomacromolecule with a carbon film comprises: functionalizing the surface of the carbon film with a PBASE / ethanol solution to form a PBASE / carbon film; Spot the antibody / PBS solution on the PBASE / carbon membrane, dry it, then use blocking solution to block the PBASE that is not bound to the antibody, and then wash it.

9. A virus detection method, characterized in that: The virus detection method comprises: Obtaining the self-heating biosensor chip according to any one of claims 1 to 5 or the self-heating biosensor chip prepared by the preparation method according to any one of claims 6 to 8; The sample solution is brought into contact with the carbon film, and the two metal electrodes are used to detect the current at both ends of the carbon film. If the current at both ends of the carbon film changes, it is determined that the sample solution contains viruses that specifically react with biological macromolecules; The carbon film is heated by the heating electrode to desorb the virus bound to the biomacromolecule.

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